The need for greater bandwidth and higher data transmission rates has motivated efforts to develop next-generation platforms for information storage and delivery. It is widely believed that optical information systems will provide superior performance to today's microelectronics-based systems. Integrated optical systems based on silicon photonics are a leading replacement technology for microelectronic systems. Silicon photonics interfaces with standard CMOS technologies and WDM (wavelength division multiplexing) to convert electrical signals to optical signals, to transmit optical signals, and to reconvert optical signals to electrical signals. In disaggregated systems, transfer of signals between units occurs through optical links that provide high bandwidth and high data transfer rates.
Deployment of silicon photonics has been limited by packaging. In order to operate efficiently, losses in the transfer of optical signals to and from silicon photonic devices need to be minimized. A proposed silicon photonics device includes a silicon chip (substrate) for receiving electrical signals and producing optical signals and an SOI (silicon-on-insulator) waveguide for coupling light from the chip to a polymer waveguide. The polymer waveguide includes a core and a cladding and transfers the optical signal to an optical link for delivery to other devices. Polymer waveguides are one preferred practical conduit for transferring light from the chip to an optical link because they offer ease of manufacturing and flexibility in design.
Efficient operation of silicon photonic devices requires low loss coupling of the optical signal from the silicon chip to the to the optical link. Success in minimizing coupling losses between the chip and polymer waveguide has been achieved through adiabatic coupling techniques. See, for example, I. M. Soganci et al., Opt. Express 21(13), 16075-16085 (2013). Although optical fibers have been used in conjunction with silicon photonic devices, insufficient progress has been made in tailoring the characteristics of optical fibers to minimize coupling losses. There is a need for new optical fibers with performance characteristics suitable for use in silicon photonics assemblies.